A recent study has shown that over half of the calories consumed by adults in the US were from major subsidized food commodities, and greater consumption of calories from these sources is associated with increased risks for cardiometabolic disease. The findings support previous calls to realign agricultural policies with nutritional guidelines to improve population health.
The U.S. Department of Agriculture and U.S. Department of Health and Human Services Dietary Guidelines for Americans emphasize consumption of vegetables, fruits, protein, whole grains, and dairy at moderate amounts, while recommending limited intake of refined grains, salt, sugars, and saturated fats. Research shows that a less than optimal diet is a leading factor associated with disability and death in the US. Specifically, diets that are high in calories, sugars, salt and saturated fats, but low in vegetables and fruits, have been linked to the development of cardiometabolic risk and diseases. Cardiometabolic risk refers to a high lifetime risk for cardiovascular disease. The specific factors that can cause this increased risk include obesity, diabetes, and elevated blood pressure.
Previous literature has shown that diets of people who consume a large proportion of foods from subsidized food commodities tended to be rich in grains, meat products, high-fat dairy and poor in vegetables and fruits and overall diet quality. Agricultural subsidies are payments made by the U.S. federal government to certain farmers and agribusinesses for the purpose of stabilizing food prices, ensuring abundant food production, guaranteeing basic incomes of farmers, and usually strengthening the agricultural sector of the economy. The focus of current federal agricultural subsidies are on financing the production of wheat, soybeans, corn, sorghum, rice, dairy, and livestock, the two latter of which are in part through subsidies on feed grains. A large fraction of these subsidized commodities are converted into refined grains, high-fat dairy and meat products, high-calorie soft drinks and juices (sweetened with corn sweeteners), and processed and packaged foods. Since about 80% of the food that Americans eat are produced by the US agricultural sector (the remaining 20% comes from imports), the foods that are made domestically have a large influence on the American diet.
Nutrition and public health professionals have suggested an association between agricultural policy and cardiometabolic risk and obesity, and have called for agricultural subsidies to be eliminated or at least to shift to crops that are healthier. However, evidence-based research showing a lack of alignment between agricultural policies and nutritional policies and recommendations in the US has been limited to ecological assessments. Furthermore, no study, until now, has looked at the association between intake of subsidized foods and cardiometabolic health at the individual level; such evidence may more correctly characterize the alignment of agricultural policies with nutritional guidelines. Thus, a group of researchers conducted a study to examine whether greater intake of subsidized foods is linked to adverse cardiometabolic risk in adults in the U.S.
The researchers used data from 2001 to 2006 from the National Health and Nutrition Examination Survey, a cross-sectional study of 10 308 adults in the general community who were 18 to 64 years old, provided complete dietary data, and had a calorie intake between 800 and 6000 kcal. The researchers calculated subsidy score at the individual level from a single day of 24 hour dietary recall in the NHANES to estimate the participants’ individual consumption of subsidized food commodities (wheat, diary, soybeans, corn, rice, and livestock) as a percentage of total calorie intake. The main measures were body mass index (BMI), glycemia, C-reactive protein level, abdominal adiposity, blood pressure, and non–high-density lipoprotein cholesterol level.
The study, published in JAMA Internal Medicine, revealed that over half (56%) of all calories consumed by adults in the US during the 6 year period (from 2001 to 2006) came from the major subsidized food commodities (wheat, diary, soybeans, corn, rice, and livestock). Additionally, adults with the highest consumption of calories from subsidized food commodities had diets with lower nutritional quality and had a greater likelihood of some risks for cardiometabolic disease. After adjusting for lifestyle and sociodemographic factors, the researchers found that those who had the highest consumption of subsidized food had an increase between 14% and 41% in the probability of cardiometabolic risk factors. Compared to participants with the lowest subsidy scores, those with the highest had a 37 percent greater risk of being obese, a 41 percent greater risk of having abdominal adiposity (fat in the abdomen), a 34 percent greater risk of having an elevated C-reactive protein level (indicates inflammation in the body), 14 percent greater risk of having dyslipidemia (abnormal cholesterol levels), and a 21 percent greater risk of having dysglycemia (abnormal blood glucose levels). No association was found between the subsidy score and blood pressure.
Taken together with data in the present study, the US government spent $170 billion from 1995 to 2010 on subsidizing the production of foods that were linked to obesity, a poor health outcome that successively was associated with increased spending for health services covered by Medicaid and Medicare. Even though eating less subsidized foods will not eliminate obesity, the researchers suggest that people whose diets are made up of a lower percentage of subsidized foods have a lower chance of being obese.
The overall findings suggest that there is currently a lack of alignment between agricultural policies and nutritional guidelines in the US; nutritional guidelines emphasize on the population’s needs for healthier foods, but agricultural policies that impact production and availability of foods have not yet done the same. Furthermore, they support that better alignment of agricultural policies and nutritional guidelines and policies may have the potential to improve the distribution of risk factors for cardiometabolic disease and improve the health of the population. The researchers assert that one way to address this need may be to shift agricultural subsidies toward production of crops that are healthier, such as vegetables and fruits.
Written By: Nigar Celep, BASc